Constraint on ion–neutral drift velocity in the Class 0 protostar B335 from ALMA observations Hsi-Wei Yen, Bo Zhao, Patrick M. Koch, Ruben Krasnopolsky, Zhi-Yun Li, Nagayoshi Ohashi and Shigehisa Takakuwa A&A, 615 (2018) A58 Published online: 13 July 2018 DOI: 10.1051/0004-6361/201732195